Safety-switch.



R. WOLFSBERG 64 S. 0. SMITH.

SAFETY SWITCH.

APPLICATION FILED APR. 30. 1917- Patented Dec. 25, 1917.

2 SHEETS-SHEET 1.

R. WOLFSBERG & S. C. SMITH.

SAFETY SWITCH.

APPLICATION nun APR. 30. 1911.

Patentd Dec. 25, 1917.

M a H. mm w W R UNITED STATES PATENT OFFICE.

RICHARD WOIIISBERG AND SIDNEY C. SMITH, 0]? LOS ANGELES, CALIFORNIA.

SAFETY-SWITCH.

Specification of- Letters Patent.

Patented Dec. 25, 1917.

Application filed April 30, 1917. Serial No. 165,434.

To all whom it may concern:

Be it known that we, RICHARD WOLFSBERG and SIDNEY 0. SMITH, both citizens of the United States, residing at Los Angeles, in

the county of Los Angeles and State of Cali- 7 fornia, have invented a new and useful Safety-Switch, of which the following is a specification.

An object of this inventionis to insure the safety from electric shock of the person operating the switch and changing the fuses thereof.

Another object is to effect the foregoing by a simple and reliable construction.

In our copending application for patent for circuit breaker filed April 4, 1917, Serial No. 159,646, some of the contacts are exposed to view when the door of the switch box is open, and the switch fuses are mounted on the door and are parts of the operating mechanism of the switch. This device differs from the foregoing described device in that the fuses are stationary and are separate from the switch members proper but the switch may be locked in open position and the door may be locked in closed position the same as in the above noted copending application. Switches of standardized construction now on the, market may be used as a portion of this present invention.

The accompanying drawings illustrate the invention:

Figure 1 is a front elevation of a safety switch embodying t e invention, said switch being locked in' the open position, the door being open and the stationary front portion being omitted.

Fig. 2 is a side elevation from the rlght of Fig. 1, the box being in section on line indicated by B -m Fig. 1 and the stationary front portion being in place.

Fig. 3 isan enlarged view of the upper through eyes 28 of hnks 29 having other portion of Fig. 2, the boX being in section, the door being closed and locked and other operating parts of the device bein in their circuit closing positions. Dotted llnes indicate the operating parts in the positions thrown as far as possible toward its circuit 1 closing position when the door is open.

Fig. 5 is a detail of the means for locking the switch open.

There is provided a fireproof housin in the form of a box comprising a top 1, ottom 2,|back 3, sides 4, 5 and a front which is partly formed by an upper stationary sect1on 6 and partly by a lower movable section in the form of a door 7 hinged at 8 to the bottom of the box. When the door 7 is closed as in Fig. 3 a tongue 9 fastened to a partition 10 of the box projects through an opening 11 in the door, so that a pad-lock 12 can engage through an eye 13 in the outer proj ecting portion of the tongue thus to'prevent opening of the door by any unauthor- .ized person. The door 7 is provided near its free edge at the inner face thereof with a tongue 14 which, when the door is closed, is disposed immediately above the partition 10. The tongue 14 is provided with an eye 15 adapted to be engaged by a detent 16 of a bell-crank lever 18 forming a latch which 15 pivoted at 19 to a bracket 20 mounted on the partition 10. The path of travel of the upper end of the lever 18 traverses the path of travel'of a switch-operating member 21 which, in the instance shown in the drawings, has a U-shaped portion pivoted at 22, 23 in the sides 4, 5- respectively of the box, one end of said member projecting outside of the box and forming a handle 24 whereby said member may be conveniently operated from the exterior of the box without it being necessary to open the door. When the handle 24 is in the circuit-breaking position shown in Fig. 2, it lies adjacent a lug 25 projecting out from the side 4 of the box, said lug being provided with an eye 26 to receive a lock, for instance the pad-lock 27. Thus the switch-operating member 21 may be locked in the circuit-breaking position.

The switch-operating member 21 passes eyes 30 to pivotally, engage eye-bolts 31 which extend through and are adjustably fastened to a switch arm 32 of any suitable form of a switch or circuit breaker indicated in generalby the character 33. The switch 33 may be of the usual knife-blade type, well known, in the art, and owing to the link and eye bolt connections with the operating member 21 said switch may be of any desiredsize, and may be of a standardized type already on the market. When the handle 24 is moved in a direction away from the lug 25 the member 21 moves the switch arm 32 toward the electric contacts 34 of the switch 33 and when said member is moved suiiiciently far the knife blades 35 of said switch engage the contacts 34 so as to close the circuit 111 amanner well understood in the art. The switch 33 need not be further described in detail herein as the construction thereof is already known in the art.

The path of movement of the switch-operating member 21 traverses the path of movement of a detent 36 forming one end of a dog 37 pivoted at 38 to a bracket 39 which may be mounted, as shown, on the partition 10 of the box. The dog 37 thus provides latching means for the member 21. The opposite end of the dog 37 lies in the path of movement of an abutment in-the form of a pin 40 projecting inward from near the free end of the door 7 and passing through a perforation 41 of the box. Thus when the door 7 is in closed position the pin 40 is engaged with the dog 3'7 so as to hold the dog out of its latching position as in solid lines in Fig. 3 so that the switch-operating member 21 may be moved to close the circuit, provided of course that the handle 24 is not locked to the ing 25. When the door 7 is not closed tightly as in Figs. 2 and 4 the lower end of the dog 37 is pressed outward by a spring 42 so as to hold the detent 36 in the path of movement of the switch-operating member 21. Thus it is clear that when the door is not shut if a person attempt to move the switch-operating member 21 from the position shown in Fig. 2 toward the position shown in Fig. 3 said switch-operating member will be held against movement suflicient to close the switch. by reason of the detent 36 engaging the-'switch operating member 21 as in Fig. 4. Not until the door is closed will the detent 36 be moved out of its latching position so as to admit of the member 21 being operated to close the switch 33.

The lever 18 is moved into and is normally held in latching position by a spring 42.

The operating parts just described are housed within the upper compartment 44 of the box, said compartment being separated from the lower compartment 45 by the partition 10. The switch 33 is connected by a conductor or conductors 46 to a fuse block 47 adapted'to hold fuses, not shown,

in a manner well understood in the art.'

Thus when the door 7 is opened it gives access tothe lower compartment 45 only, so that the fuses may be renewed when necessary or desirable, and as above noted the door can only be opened when the switch arm 32 has been moved into the latched circuit-breaking position. Also said switch arm 32 after being moved into the latched circuit-breaking position to admit of opening of the door cannot be again operated to close the circuit so long as the door 7 is open.

In practice ordinarily the door 7 will be locked in closed position by the lock 12 and to open and close the switch 33 the handle 24 will be operated toward and from the lug 25. If workmen are employed on the line in which the device is in circuit the switch will be locked in circuit-breaking position by the lock 27.

If it becomes necessary or desirable to change the fuses in the fuse block 47, the authorized operator will unlock the lock 12 and remove the same and will then open the door 7 so as to give access to the compartment 45 in which the fuse block is situated. He will then change thefuses without any liability of receiving an electric shock since the switch arm 32 cannot be thrown into circuit-closing position while the door remains open.

After changing the fuses the operator will.

close the door 7 thus causing the pin 40 to operate the dog 37 to move the detent 10 from the position shown in Fig. 4 to the position shown in solid lines in Fig. 3 so that the switch 33 may be closed. WVhen the door is thus moved into closing position the tongue 15 is engaged by the detent 16 so that the door cannot be again opened until the switch-operating member 21 has been moved into the door-releasing position shown in Fig. 2 and indicated in dotted lines in Fig. 3.'

We claim:

1. In combination, a box having two compartments and a door for one of said compartments, a fuse block in the compartment having the door, a switch in the other compartment, a tongue on the door, a lever pivoted in the closed compartment and having a detent to engage the tongue when the door is closed, an operating member for the switch extending outside of the box and connected to the switch, the path of movement of the operating member traversing the path of movement of the lever, a dog pivoted in the closed compartment and havlng a detent at one end, thepath of movement of said last named detent traversing the path of movement of the operating. member, means to normally hold the dog with its detent in the path of movement of the operating member, means to tend to hold the lever with its detent in door-latching position, and means on the door adapted to'engage the lever to move its detent out of latching position.

2. In combination, separate compartments, a switch in one of the compartments, a fuse block in the other compartment, a U-shaped member pivoted in the side of the switch compartment and havingahandle extending having one end in the path of travel of the outside of said compartment and connected U-shaped member, and means tending to to the switch to operate said switch, a dog, hold the detent in tongue-engaging position.

means to move the dog in the path of travel Signed at Los Angel'es, California, this 1.5 5 of the U-shaped member, a door for the fuse 24th day of April, 1917.

block compartment, an abutment on the v door to engage the dog to movethe dog out i% of the path of travel of the U-shaped memv i her, a tongue on the inside of the door, a Witnesses: 10 pivoted lever in the switch compartment GEORGE H. HILEs,

having a detent to engage said tongue and A. F. SCHMIDTBAUER. 

